If you’ve ever visited underground caverns (or ridden a subway), you know that getting from Point A to Point B underground (hence, without the stars, sun, or landmarks for assistance) over any meaningful distance requires planning and intelligence. This is yet another telling find documenting the intelligence and applied aptitude of ancient humans. Sure, prehistoric people weren’t using electricity or computers, but they weren’t sitting on their duffs waiting for star visitors to solve their problems, either.